Lifting dolly



Dec. M, 1935. R. L. DAVIS ET AL 2,23,410

LIFTING DOLLY Filed Feb. 15, 1955 (innngnamm INVENTORS.

Patented Dec. 10, 1935 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to an adjustable lifting dolly, and has for its principal object the provision of a wheeled dolly which will also serve as an efiicient lifting jack for safely and easily elevating and transporting heavy objects. The invention is principly designed for installing household appliances such as gas ranges, refrigerators, etc. With its use, a gas range can be wheeled into the kitchen, conveniently and easily without damage to the floors or Walls. It can then be easily and quickly rolled directly into place and lowered to the floor at its proper position. It is especially useful for installing gas ranges into wall niches where it is impossible to reach either end of the range.

Other objects of the invention are to so construct the device that it will be compact; will fold to a relatively low position and elevate to a relatively high position; and will be absolutely rigid when elevated.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a perspective view of the improved lifting dolly in the fully elevated position.

Fig. 2 is a similar view thereof in the lowered position.

The invention comprises: a lower frame IE! provided with suitable caster wheels Across each extremity of the lower frame l, a hinge bolt i2 extends. Two lower toggle arms I3 extend upwardly from each extremity of each hing-e bolt. The toggle arms l3 are spaced on the hinge bolts by means of spacing sleeves l4 around the bolts.

The upper portion of the dolly consists of an upper frame l5 preferably exactly similar in construction to the lower frame H). The upper frame is also provided with hinge bolts Hi from which upper toggle arms l] extend downwardly. 'The upper pairs of toggle arms I! are joined to the lower parts of toggle arms I3 by means of cap screws i8, which are threaded into a separating member E9. The screws l8 are prevented from loosening in the members IQ in any desired manner, such as by means of cotter keys 2!! which pass through the members l9 and the screws.

The separating members I9 are formed with internally threaded sleeves which align with each other and through both of which a threaded jack 5 shaft 2i extends. The jack shaft 2| is formed with a left hand thread at one extremity and a right hand thread at the other extremity, so that as it is rotated, the two separating members l9 will move toward or away from each other so as 10 to operate the toggle arms l3 and H. A universal joint stud 30 is provided in the shaft extremity for receiving a crank or handle for rotating the shaft.

A flanged sleeve 22 is looked upon the jack l5 shaft 2| at its middle by means of suitable lock nuts 23. This sleeve passes through slotted openings 24 in a pair of brace members 25. Flanges 26 on the sleeve 22 prevent longitudinal movement of the brace members upon the jack screw 2|. The brace members are hinged to the lower and upper frame members respectively, by means of suitable hinges 21 and 28 and act to prevent end sway of the upper frame over the lower frame.

It can be seen that any endwise movement of the upper frame will be carried from one brace member to the other through the flanged sleeve 22 so that both frames will be rigidly locked above each other, and yet will be free to sep- 30 arate.

In use, the dolly, in the position of Fig. 2, is wheeled under the article, such as a range or a refrigerator. The jack screw is then rotated to cause the two members H! to move away from each other. This movement causes the toggle arms l3 and I! to gradually approach alignment with each other, and in so doing, they elevate the upper frame I5 and the article resting thereon.

The lowering operation consists simply of a reversal of rotation of the jack shaft 2|. As the frame separates, the jack shaft will travel outwardly in the slots 24 of the brace members 25 to the extreme position of Fig. 1.

It is desired to call particular attention to the fact that the entire upper structure of the dolly, including the frame, the toggle arms, the brace member, the hinges, etc., is an exact duplicate of the lower portion thereof. This greatly simplifies manufacture and reduces manufacturin costs.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied,

within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. A lifting dolly comprising: a lower frame; caster wheels supporting said lower frame; a first pair of hinged toggle arms extending upwardly from each extremity of said lower frame; an upper frame; a second similar pair of hinged toggle arms extending downwardly from each extremity of said upper frame; a separating member at each extremity; hinge members joining the two pairs of toggle arms at each extremity to said separating member; an internally threaded sleeve on each separating member; a threaded shaft extending through both sleeves and being oppositely threaded at each extremity so that rotation of said shaft will move said separating members to actuate said toggle arms; a brace member hinged to each frame, said brace members extending to said threaded shaft; and means on said shaft for preventing endwise movement of said brace members thereon.

2. A lifting dolly comprising: a lower frame; caster wheels supporting said lower frame; a first pair of hinged toggle arms extending upwardly from each extremity of said lower frame; an upper frame; a second similar pair of hinged toggle arms extending downwardly from each extremity of said upper frame; a separating member at each extremity; hinge members joining the two pairs of toggle arms at each extremity to said separating member; an internally threaded sleeve on each separating member; a threaded shaft extending through both sleeves and being oppositely threaded at each extremity so that rotation of said shaft will move said separating members to actuate said toggle arms comprising: a brace memberhinged to one side of the upper frame and extending inwardly and downwardly therefrom; a similar brace member hinged to the other side of the lower frame and extending inwardly and upwardly therefrom, said brace members containing slotted openings, said threaded shaft passing through said openings; and flanges projecting from said shaft so as to prevent endwise movement of said brace members thereon.

3. A lifting dolly comprising: a lower frame; an upper frame; toggle arms separating said two frames; a threaded shaft for actuating said toggle arms to separate said frames; a brace member hinged to the opposite side of each frame so that together they extend diagonally across said dolly; and means for preventing endwise movement of the free extremities of said brace members.

ROBERT L. DAVIS. JACK'MCGINNIS. 

